A commonly used loose leaf fastener for holding a stack of pages in a legal file folder or a business correspondence file folder is the two-piece metal "ACCO" fastener, sold by ACCO International Inc., Chicago, Ill. This fastener has a base piece with bendable prongs at its opposite ends, and a top piece with openings for receiving the prongs and sliders for holding the prongs folded down on the top piece. When a relatively thick stack of pages is held by this fastener in a file folder, it often is difficult to keep the stack open to a selected page, for example, when the user wants to read from a page somewhere toward the middle or bottom of the stack. To overcome this problem, the user may remove the top piece of the fastener and then slide all the pages in the stack above the selected page off the prongs of the base piece of the fastener, leaving the selected page exposed for reading. However, this has the disadvantage that the prong-receiving openings in the removed pages must be re-aligned before these pages can be put back in, and this often is time-consuming and troublesome.